螺距对支抗微种植体—骨界面影响的三维有限元分析

Three-dimensional finite element analysis for the influence of micro-implant pitch on micro-implant-bone interface

目的分析螺距变化对微种植体—骨界面、微种植体的应力分布和位移的影响,为支抗微种植体的临床选择和优化设计提供理论参照。方法运用Pro/E软件建立不同螺距的微种植体和下颌骨三维有限元模型,用Hypermesh软件对该模型进行网格划分,并在微种植体顶部施加与颌骨面平行的正畸力1.96 N,用ANSYS软件进行三维模拟计算。结果微种植体—骨界面应力峰值集中在微种植体颈部和尖部,当螺距为0.5 mm时,微种植体颈部的Vonmises应力和位移峰值最小,分别为27 MPa和0.001 5 mm,且应力和位移曲线最为平缓。结论螺距变化影响微种植体和微种植体—骨界面的应力分布。在本实验条件下,螺距为0.5 mm时,微种植体—骨界面、微种植体本身应力和位移最小。

Objective To analyze the stress distribution at micro-implant-bone interface and the displacement of micro- implant based on different pitch and to apply the theoretical reference for choosing orthodontic anchorage micro-implant and optimize design of micro-implant. Methods The three-dimensional finite element models of micro-implant with different pitches and mandible were established by Pro/E; the elements were divided by Hypermesh. The force of 1.96 N was applied on the top of the implant parallel to the mandible surface to analyze the differences of the micro-implant displacement and that of the force on the micro-implant-bone interface. Results The maximum Von-mises stress focused on the neck and tip of micro-implant. The peak Von-mises stress and displacement on the neck of micro-implant are both the smallest, which are 27 MPa and 0.001 5 mm respectively, and the stress and displacement curves are the flattest at the pitch of 0.5 mm than that of other sizes. Conclusion The pitch of micro-implant influences the stress distribution on micro-implant and bone surface. The stress and displacement on both micro-implant-bone interface and micro-implant are both the smallest in the 0.5 mm case of other micro-implant parameters in this work.